This invention relates to a wave generator for a digital type electronic musical instrument.
Musical tone waveforms generated by ordinary musical instruments are intricately changed with the lapse of time.
In a conventional electronic musical instrument, an envelope is given to a musical tone waveform generated by the operation of a key in the keyboard, for the period of time of from the time instant when the musical tone wave rises to the time instant when it is ended, thereby to produce a musical tone. This envelope is varied in response to the on-off operation of a key, that is, it is very simple. In addition, the musical tone waveform itself is maintained unchanged for the period of time of from its rising time to its ending time. Thus, the produced musical tone is fixed with respect to the lapse of time.
Accordingly, the musical tones produced by the conventional electronic musical instrument are monotonous when compared with those produced by the ordinary musical instruments, and feel unnatural.
The above-described envelope and waveform given to musical tones in the conventional electronic musical instrument cannot be readily changed after it has been manufactured. This is also one of the disadvantages accompanying the conventional electronic musical instrument.